I did some additional head scratching and searching and now realize what I've always thought about lower gear ratios was backwards. I've always assumed that lowering the gearing would make the tires spin easier on launch, and this isn't the case. It's actually the opposite.

It takes more engine RPM now to get the tires to turn as fast as before (duh, I know). Now that the tires spin slower on launch, I get a more a more controlled tire spin, and the car still manages a decent 0-60 even spinning. Before the swap, the tires would sometimes spin violently if I got too aggressive on the launch, which would kill the 0-60.

Anyway, I feel really dumb for having such a misunderstanding of gearing, but I'll get over it... one launch at a time.